1. Field of the Invention
The invention relates to a joint brace and more particularly a knee joint brace for preventing torsion of a distal extremity in relation to a proximal extremity connected therewith articulatingly.
2. Brief Description of the Background of the Invention Including Prior Art
Joint braces of this type are known as knee orthoses, and for example are applied following cruciate ligament operations, with the purpose of precluding a rotary movement of the lower leg in relation to the upper leg. The splints running along either side of the knee are joined together articulatingly at the level of the knee and at their free ends are firmly strapped to the upper and, respectively, lower leg. The rotary joint then permits flexion and extension of the leg for a certain, adjustable range of pivoting.
It is furthermore a practice to limit the range of pivoting of the splints and accordingly of the knee joint in a predetermined, variable fashion. This may for instance be done by the insertion of shims or wedges with different sizes between the abutment of one splint and the complementary abutment of the further splint connected therewith. A further practice is to insert an abutment pin in different holes in accordance with the desired range of pivoting, such holes being provided in one of the splints connected together.
In the case of these known joint braces it is a disadvantage that any increase or reduction in the free pivot range is only possible in relatively large angular steps. For example in the case of a conventional knee brace the limitation of the pivoting in the extension direction, i. e. in the stretch out direction of the extremities of the body, adjustment is only possible to set to four different positions, i. e. in 15.degree. steps between 0.degree. and 45.degree.. The 0.degree. setting then corresponds to the completely straight, extended position of the lower leg in relation to the upper leg. The U.S. Pat. No. 4,463,751 discloses a joint brace in accordance with the preamble of claim 1, in the case of which two interiorly placed, circular adjustment disks are employed having recesses for limiting the extension or, respectively, flexion of the distal splint. Pins extend through the recesses and move, together with the distal splint, within the recesses and in the respective end positions abut against abutment faces in the recesses.
Furthermore the U.S. Pat. No. 3,732,862 discloses a foot joint brace, which renders possible upward motion of the tip of the foot, whereas lowering thereof below a certain basic position is to be prevented. This known foot brace possesses a rotatably mounted pivot part with a lower abutment and a plurality of upper through holes in order to hold such pivot part by means of a setting pin at different angles of inclination in relation to a lower leg splint.
The U.S. Pat. No. 2,883,982 discloses a knee joint brace in the case of which two contacting faces on the distal and proximal splints are designed in the form of gear teeth and possess faces in rolling engagement with one another. In this case the extended position is limited by means of a tie, whose one end is secured within a slide recess means in the proximal splint and whose other end is pivotally secured to the distal splint. These last-named splints are however complex in design are furthermore expensive and are difficult to manipulate. Moreover, they are unsuitable for stretching the joint in question should its mobility be impaired owing to ligament surgery, injuries, inflammation and the like and the joint capsule and/or connective tissue be defective as regards extension or flexion.